What do you mean by common media forms?

Common - meaning occurring, found, or done often; not rare.

Media - meaning the means of Mass Communication, especially television, radio, and newspapers collectively; means by which something is expressed, communicated, or achieved; forms of storage for computer software, such as magnetic tape or disks. The Word media comes from the Latin plural of medium.

Forms - meaning a way in which a thing exists or appears.

Therefore common media forms traditionally include television, radio, and the press but also more modern forms such as the internet and twitter, computerhard drives, removable drives (such as Zip disks), CD-ROM or CD-R discs, DVDs, flash memory, and USB drives